Single Database or Multiple Databases (2 posts)

I am in the process of creating a website that will have multiple blogs. Since each blog will have its own unique navigation menu and each blog will have its own administrator, I am going to have multiple installs of wordpress in separate folders.

I see here http://codex.wordpress.org/Installing_Multiple_Blogs that it give instructions on how to perform multiple installs of WordPress. However, when I created my second blog, I simply created a folder and installed WordPress in it using the automatic WordPress install in my Bluehost cPanel.

I am assuming that this would have created a separate database within the folder for the new WordPress install. Is this correct?

Also, I am not really sure of the advantages or disadvantages of creating separate databases for each install compared to a single database for all installs. Eventually I hope to have 100 or even 200 blogs. Would separate databases or a single database be the best option for me?